Overall expression of beta-catenin outperforms its nuclear accumulation in predicting outcomes of colorectal cancers.
OBJECTIVE
To examine the expression of beta-catenin in colorectal cancer and look for association with other clinico-pathological parameters.


METHODS
Tumor samples from 163 cases of colorectal cancer (CRC) who had undergone primary colectomy between May, 1998 and November, 2002 with complete follow-up data for either 5 years or until death were recruited for a beta-catenin immunohistochemical study. The percentage of immunoreacted tumor cells was defined as overall staining density (OSD) and percentage of cells having nuclear localization was counted as nuclear staining density (NSD). Univariate exploration used log-rank test and multivariate survival analysis used Cox's hazard regression model.


RESULTS
Beta-catenin immunoreactivity was detected in 161 samples (98.8%), of which 131 cases had nuclear staining. High OSD (> or = 75%), detected in 123 cases (75.5%), was significantly associated with earlier clinical staging (P < 0.01), lower nodal status (P = 0.02), non-metastatic status (P < 0.01) and better differentiation (P = 0.02). Multivariate analysis found that high OSD was independently associated with better survival [Cox's hazard ratio 0.51, 95% confidence interval (CI) 0.31-0.83]. Although high NSD (> or = 75%) was correlated with high pre-operative serum CEA (P = 0.03), well differentiation (P < 0.01), and increased staining intensity (P < 0.01), the parameter was not significantly associated with survival.


CONCLUSIONS
Unlike previous reports, the study did not find a predictive value of nuclear beta-catenin in CRC. Instead, the overall expression of beta-catenin in CRC showed an association with better differentiation and earlier staging. Moreover, the parameter also independently predicted superior survival.
Wanitsuwan
Worrawit
W
Department of Surgery, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, 90110 Thailand.
Kanngurn
Samornmas
S
Boonpipattanapong
Teeranut
T
Sangthong
Rassamee
R
Sangkhathat
Surasak
S
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D051176:beta Catenin / Q000378:metabolism*
D014408:Biomarkers, Tumor; D051176:beta Catenin